Originally Posted by
RatherBeFlying
It appears that MCAS can in ten seconds move the stab whenever it's in the mood, but the pilots need considerably longer to bring back the stab with dozens of cranks of manual trim - provided that airload allows them to move the trim.
...... The software will have to get even fancier to satisfy 10E-9 reliability.
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There is no such requirement applicable, besides you probably wouldn't believe it anyhow.
It's really a balance between the pilot and the design. If the pilot can't be relied on, then the design is not good enough